The present invention relates to tubes insertable within the human body. In particular, the present invention relates to a tracheostomy tube for insertion within a neck of a patient.
Tracheostomy tubes have been used for many years to provide an airway in a patient with specific respiratory difficulties. The tracheostomy tube provides access to the trachea below the larynx in the neck of a patient. The primary objective in using a tracheostomy tube is to provide adequate airway ventilation. The tube can permit passive ventilation, i.e., ventilation occurring without assistance. Alternatively, the tracheostomy tube can provide access for mechanically assisted ventilation for patients that are unable to breath on their own.
Conventional tracheostomy tubes are relatively long and are formed in the shape of a gradual curve such that opposite ends of the tube are disposed at a large angle (e.g., 90.degree.) relative to one another. The conventional tracheostomy tube is generally made of hard plastic and can include an expandable and collapsible cuff disposed at the inserted distal end of the tube. The expandable cuff, when expanded, acts to secure an inserted distal end of the tube within the trachea. A proximal end of the tube is typically secured to the exterior surface of the neck with a bracket wherein an elastic band or tie is fastened to the bracket and extends around the neck of the patient to anchor the bracket and proximal end of the tube relative to the trachea. This method of securing the tracheostomy tube results in a relatively loose fit of the tube within the trachea. Amongst other difficulties, this loose fit makes it difficult to obtain adequate air pressure when providing mechanically assisted ventilation through the tracheostomy tube.
In addition, conventional tracheostomy tubes are undesirable to use because they typically include an inflation tube or other inflation means which must extend from the expandable cuff to the proximal end of the tracheostomy tube to provide for inflation of the cuff. This typically results in the inflation tube extending outwardly from the exterior surface of the neck creating an unsightly appearance. Moreover, conventional tracheostomy tubes are designed such that the proximal end of the tube extends outwardly from a bracket mounted on the neck of the patient, which further contributes to the unsightly appearance of the tracheostomy tube within the neck of the patient. In addition, conventional tracheostomy tubes are designed to allow insertion of a cannula through the tracheostomy tube wherein a proximal end of the cannula locks to the proximal end of the tube. This design results in a proximal end of the cannula extending even further outwardly from the bracket than the proximal end of the tube. Obviously, this further contributes to the unsightly appearance of conventional tracheostomy tubes.
Conventional tracheostomy tubes have a continuous side wall made of hard plastic which is relatively inflexible and which tends to make insertion of the tracheostomy tube difficult. Insertion of the conventional tracheostomy tube typically requires an obturator insertable through the tracheostomy tube to temporarily provide a rounded tip portion at the distal end of the tracheostomy tube during insertion of the tube through the stoma and into the interior of the tracheal lumen.
Conventional tracheostomy tubes also complicate the patient's breathing because of the relatively long portion of the tracheostomy tube which extends down into the trachea. This long tube makes breathing more difficult as well as complicating or hampering the ability of a patient to expel excess mucous by the coughing reflex.
Finally, several sizes of conventional tracheostomy tubes must be available on demand to accommodate different sized tracheal stomas. This requires shelf storage of several different size tracheostomy tubes increasing inventory costs and resulting in tubes which exceed their sterility limit for shelf storage.
Various attempts have been made to improve upon the conventional tracheostomy tube. For example, U.S. Pat. Nos. 3,263,684, 3,137,299, and 5,287,852 all provide examples of relatively straight non-conventional tracheostomy tubes designed to avoid a tracheostomy tube having a long portion extending downwardly into the lumen of the trachea. This relatively straight tube design avoids significant contact between the distal end of the tracheostomy tube and the mucous lining on the tracheal wall. This aids in preventing infection of the trachea and bronchial tree as well as avoiding damage to the cilia which acts to move excess mucous upward through the trachea for eventual expulsion through the tracheostomy tube or the mouth.
These non-conventional tracheostomy tubes still have several features which detract from their performance and general desirability of use. These non-conventional tracheostomy tubes each include a significant portion of the tube that extends outwardly from the neck of the patient creating a rather unsightly and noticeable cosmetic appearance bringing unwanted attention to the patient by curious observers. Moreover, although these non-conventional tracheostomy tubes avoid some of the disadvantages of the conventional tracheostomy tubes, these non-conventional tracheostomy tubes have not been widely accepted in the marketplace. This could result from their unsightly cosmetic appearance or from other functional considerations. One functional consideration is how well the tracheostomy tube is secured within the stoma through the neck of the patient into the trachea. The Tabor U.S. Pat. No. 3,137,299 and Bolton U.S. Pat. No. 3,263,684 each disclose non-conventional tracheostomy tubes which require the use of an elastic band or cord to pass around the patient's neck for securing the tracheostomy tube relative to the trachea and neck. It is desirable to avoid the use of this securing band or cord which brings unwanted attention to the patient and which can be uncomfortable or bothersome for the patient to wear. Another functional consideration includes ease of insertion and removability of the tracheostomy tube through the stoma and into the trachea. Although some of the non-conventional tracheostomy tubes are made of materials which may be resilient, these non-conventional tracheostomy tubes fail to include design features that significantly aid in the insertion and removal of the tracheostomy tube within the stoma. Moreover, even the resilient tubes, which may facilitate insertion somewhat, can be less desirable once seated within the stoma because the resilience of the materials may cause the tracheostomy tube to be less stable relative to the trachea.
In addition, the relatively straight tube design can make it more difficult to pass accessory devices through the tracheostomy tube down into the trachea. The straightness of the tube tends to direct any accessory device inserted therein into the posterior wall of the trachea opposite the location of the tube within the anterior wall of the trachea.
Accordingly, tracheostomy tubes of the prior art have many limitations. First, conventional tracheostomy tubes having a long tubular portion which extends down into the trachea tending to obstruct the lumen of the trachea as well as potentially damaging the cilia and bronchial tree. These conventional tracheostomy tubes also typically fit loosely within a tracheal stoma and require an extra elastic band to pass around the neck of the patient to secure the tracheostomy tube relative to the trachea. A proximal end of the conventional tracheostomy tubes also typically protrude outwardly from the skin surface of the neck and along with the elastic band placed around the neck of the patient, create an unsightly appearance attracting unwanted attention from curious observers. The securing band can be uncomfortable.
Even non-conventional tracheostomy tubes (relatively straight tubes) have many limitations. Like the conventional tracheostomy tubes, the relatively straight tubes also protrude outwardly from the skin surface of the neck and some require elastic bands to be placed around the neck, thus still creating an unsightly appearance for the patient. The relatively straight tracheostomy tubes make it more difficult to insert cannulas and other accessory devices through the tracheostomy tube because no means are provided for guiding the accessory device or cannula downward into the trachea. Therefore, the non-conventional relatively straight tracheostomy tube tends to cause accessory devices in cannulas to contact the posterior wall of the trachea upon insertion. Finally, although some conventional tracheostomy tubes as well as non-conventional tracheostomy tubes are resilient, insertion and removal of these prior art tracheostomy tubes is still difficult to achieve when inserting a tracheostomy tube that is properly sized to result in a snug fit within a tracheal stoma. Last, both conventional and non-conventional tracheostomy tubes of the prior art require a full range of sizes be kept in inventory so the proper sized tracheostomy tube is available for any given tracheal stoma.